In tilling soil, such as when planting seed, eliminating weeds, or preparing the soil for planting or treating crops, implements are used which are designed to be pulled behind a source of tractive power, such as a tractor or crawler. These implements may take several forms but chisel tooth plows, sometimes known as field cultivators, rod weeders, spring tooth cultivators, blade cultivators, and disc cultivators are common. While generally acting as intended under operating conditions in the field, these implements present problems when it is desired to transport them between two fields located in non-contiguous area. Frequently, the implements may have to be transported over public roads, under wires or bridges or through tunnels or culverts where the implement is not designed to go. Obviously undesirable are the safety and size characteristics inherent in such equipment.
Various manufacturers have produced equipment designed to overcome these deficiencies. It is known, for example, that an implement comprising several frame sections located on opposite sides of the longitudinal axis of the implement may have a longitudinal axis about which the end sections on each side of the implement rotate first upwardly and then inwardly. This technique, while it reduces the width of the implement behind the tractor and may, therefore, meet either legal or other width transportation requirements in effect for public roads, increases the height of the implement which may create problems in going under wires or low bridges or through tunnels or culverts. Furthermore, this type of implement is inherently dangerous to pedestrians and other vehicles in the vicinity of the transported implement because the tillage tools are directly exposed on both sides of the transported implement. Further, the implement requires a hydraulic system capable of rotating the heavy and unwieldy several frame sections upwardly and, if the hydraulic system should fail, or, for some other reason, the frame sections fall either while being raised to their transportable positions or while the implement is being transported, injury and damage may result. Despite the reduction in width of the transported implement by using the "wing up" design, the trend today is towards larger implements as increased tractive power becomes available. As extra frame sections are added, the width increases as well as the height.
Thus, if legal or practical limitations exist on the width or height of the implement when being transported, the size of the implement may be undesirably restricted.
A further disadvantage of present tillage implements is that the reinforcing means used to provide bracing between the tongue of the implement and the various frame sections extends forwardly from the frame section. As additional frame sections are added, the reinforcing means must extend further outwardly from the longitudinal axis of the implement. Thus, unless the opposite end of the reinforcing means is moved forwardly, the effectiveness of the reinforcing means decreases. This may, therefore, necessitate a greater tongue length which increases the distance of the tillage tool from the tractor. With this increased length between the tool and the tractor, the contour of the ground is not followed as closely as is possible and unnecessary tillage depth or no tillage at all may result.
Other manufacturers have produced implements which, after being operated, are transported by disconnecting the tongue from the tractor and reconnecting the tractor to one of the transverse ends of the implement. Thus, the implement is transported behind the tractor by one of the transverse ends which reduces the transverse width of the implement exposed beyond the sides of the tractor.
There are, however, unnecessary problems existing in this implement design as well. The operator must leave the tractor and move it both to disconnect the operating hitch from the implement and to connect the transport hitch. The wheels beneath the implement must be designed to castor since the implement is pulled by the tractor both transversely and longitudinally. While this usually does not substantially affect the implement under operating conditions, the track of the implement while under transport may be of concern. Further, because the length of the implement is the same as its transverse width, the length under transport may create unnecessary unsafe conditions such as when pulling the implement around tight corners.
According to the present invention, there is disclosed an implement used for tillage purposes comprising a tongue adapted for connection at one end to a source of pull power, a centre frame connected to the opposite end of said tongue, sub-frames connected to said centre frame on respective opposite sides of said centre frame by substantially horizontal axes which are adapted to allow independent vertical movement of said sub-frames relative to said centre frame, a plurality of end frames attached to said sub-frames and extending outwardly therefrom in a generally diverging V-shaped configuration, said end frames being interconnected by substantially horizontal axes adapted to allow independent vertical movement of each respective end frame relative to its adjoining end frame, said end frames being adapted for pivotal rotation about substantially vertical wing-back pivot points located on said sub-frames on respective opposite sides of the centre of said implement, wheel means mounted below said centre frame, said sub-frames and said end frames to allow movement of said implement, the wheel means on said centre frame and sub-frames operating independently of the wheel means mounted on said end frames, and reinforcement members moveable between extended and retracted positions and being located symmetrically on opposite sides of the centre of said implement, one end of each of said reinforcement means being rotatably mounted on said centre frame behind said wing-back pivot points and the other of each respective end being rotatably mounted on one of said end frames, whereby said implement is adapted for operation when said reinforcement means is extended and for transportation when retracted.